Al Lewis acid-catalyzed regiodivergent 1,2-rearrangement of α-siloxy aldehydes: scope and mechanism
摘要:
Regiodivergent 1,2-rearrangement of alpha-siloxy aldehydes bearing alpha-aryl and alpha-alkyl substituents into alpha-siloxy ketones has been realized by using different Al Lewis acid catalyst/solvent systems. The scope of this unprecedented protocol has been investigated with various substrates, clearly demonstrating its utility for the selective synthesis of two structural isomers from one substrate. Controlled experiments proved that the regiodivergency resulted from the switch of the migrating group. (C) 2009 Elsevier Ltd. All rights reserved.
Al Lewis acid-catalyzed regiodivergent 1,2-rearrangement of α-siloxy aldehydes: scope and mechanism
摘要:
Regiodivergent 1,2-rearrangement of alpha-siloxy aldehydes bearing alpha-aryl and alpha-alkyl substituents into alpha-siloxy ketones has been realized by using different Al Lewis acid catalyst/solvent systems. The scope of this unprecedented protocol has been investigated with various substrates, clearly demonstrating its utility for the selective synthesis of two structural isomers from one substrate. Controlled experiments proved that the regiodivergency resulted from the switch of the migrating group. (C) 2009 Elsevier Ltd. All rights reserved.
Enantioselective synthesis of protected α-hydroxy aldehydes and ketones via hydroxylation of metalated chiral hydrazones
作者:Dieter Enders、Vidya Bhushan
DOI:10.1016/s0040-4039(00)87901-0
日期:1988.1
α-Benzyloxy aldehydes and α-acetoxy ketones 4 of high enantiomeric purity are prepared in good overall yields via oxaziridine mediated hydroxylation of chiral hydrazone azaenolates. As auxiliaries novel proline derived hydrazine reagents 5 are used.
Enantioselective Aerobic Oxidation of α-Hydroxy-Ketones Catalyzed by Oxidovanadium(V) Methoxides Bearing Chiral, <i>N</i>-Salicylidene-<i>tert</i>-butylglycinates
作者:Chien-Tien Chen、Jun-Qi Kao、Santosh B. Salunke、Ya-Hui Lin
DOI:10.1021/ol1024053
日期:2011.1.7
Chiral oxidovanadium(V) methoxides prepared from 3,5-disubstituted-N-salicylidene-l-tert-butylglycines and vanadyl sulfate in air-saturated MeOH serve as highly enantioselective catalysts for asymmetric aerobic oxidations and kinetic resolution of alkyl, aryl, and heteroaryl α-hydroxy-ketones with differed α-substituents at ambient temperature in toluene or TBME (tert-butyl methyl ether). The best
Regiodivergent 1,2-rearrangement of alpha-siloxy aldehydes bearing alpha-aryl and alpha-alkyl substituents into alpha-siloxy ketones has been realized by using different Al Lewis acid catalyst/solvent systems. The scope of this unprecedented protocol has been investigated with various substrates, clearly demonstrating its utility for the selective synthesis of two structural isomers from one substrate. Controlled experiments proved that the regiodivergency resulted from the switch of the migrating group. (C) 2009 Elsevier Ltd. All rights reserved.